kérem vs kérek
I'm confused on when to use these words. For example, I think "egy sört kérek" (one beer, please) vs "kerem" (please). Are kérek and kerem interchangeable?
--When you say "kerek", it is similar to when you say I want a/one/some: book, cup, bread...etc. Non-specific. --When you say "kerem", you are talking about a specific item you are asking for. I want that book, or I want the salt (over there)... You can also use it when you are addressing people in a sentence: I want my family to...kerem a csaladom... (I don't "want" a family, I want my family "to"... etc
I hope this make sense.
There are after all three forms: kérek, kérem and kérlek.
The comments of zmanent and garpike allready explain the difference between the definite and indefinite object (of the wish you have).
But "kérem" has also the meaning of "Can you please...?" in the meaning of the formal you, the polite form.
Kérem, adjon 1000 forintot? - Can you give me 1000 Forint please?
If you want to ask the same question without useing the polite form (without being formal) , you have to use "kérlek".
The suffix "-lek" is a special one, that implies the first person singular as the subject and the second person singular as the object.
'Kérem' is the definite conjugation, when the direct object in question is specific ('a sört kérem', 'I want the beer'), or when a particular 3rd-person object is implied ('I want it'), which is presumably how it came to mean something like 'please' ('egy sört kérek' literally means just 'I want one beer; 'please' isn't a direct translation).
I seem to remember that a few definite verbs do occur in the course before the skill that covers (and explains) them, which is just after the second checkpoint.